Effect of major abdominal operations on energy and protein metabolism in infants and children.
OBJECTIVE
The authors attempted to test the hypothesis that infants and children increase whole-body protein flux and energy metabolism during the early postoperative period.


METHODS
Ten infants and children (age range, 2 days to 3 years; weight range, 1.5 to 14.2 kg) who had undergone a major operation were studied. Anaesthesia was standardised, and operative stress score (OSS) recorded. Patients were studied for 4 hours preoperatively and for the first 6 hours after surgery. Respiratory gas exchange was measured by computerised indirect calorimetry. The components of whole-body protein turnover were estimated by giving an intravenous infusion of [1-13C]leucine, and by measuring the isotopic enrichment of plasma [13C]alpha-ketoisocaproic acid by gas chromatograph mass spectrometry and 13CO2 enrichment by isotope ratio mass spectrometry.


RESULTS
Median duration of the operation was 73.5 minutes (range, 28 to 285 minutes) with a OSS of 8 (range, 7-17). There were no significant differences in oxygen consumption and resting energy expenditure between the two study phases. The respiratory quotient (RQ) fell from a preoperative value of 0.92 (range, 0.81 to 1.08) to 0.89 (range, 0.79 to 0.95) postoperatively (P = .04). The authors found no significant differences in the rates of whole body protein flux, protein synthesis, amino acid oxidation, and protein degradation between the study phases.


CONCLUSIONS
Infants and children do not increase their whole-body protein turnover and metabolic rate after major operations. The observed decrease in RQ reflects mobilisation of endogenous fat. We speculate that the lack of catabolism observed in children is caused by a diversion of protein synthesis from growth to tissue repair.
Powis
M R
MR
Department of Paediatric Surgery, Institute of Child Health and Great Ormond Street Hospital for Children, London, England.
Smith
K
K
Rennie
M
M
Halliday
D
D
Pierro
A
A
D000005:Abdomen / Q000601:surgery; D002151:Calorimetry; D002247:Carbon Isotopes; D002675:Child, Preschool; D004734:Energy Metabolism; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007930:Leucine; D011184:Postoperative Period; D011300:Preoperative Care; D011506:Proteins / Q000378:metabolism*; D011659:Pulmonary Gas Exchange; D013312:Stress, Physiological / Q000378:metabolism*; D013514:Surgical Procedures, Operative; D013997:Time Factors
D002247:Carbon Isotopes; D011506:Proteins; D007930:Leucine